In general, a refrigerator is an appliance which includes storage compartments and cooling air supply units which supply cooling air to the storage compartments and thus maintains the freshness of stored food. The refrigerator may further include an ice-making chamber and an ice-making unit for generating ice.
An automatic ice-making unit includes an ice-making tray which stores ice-making water, an ejector which separates ice made by the ice-making tray, an ice-separating heater which heats the ice-making tray when the ice is separated from the ice-making tray, and an ice bucket which stores the ice separated from the ice-making tray.
Among ice-making methods for cooling ice-making water, a direct cooling method has a refrigerant pipe provided to extend into an ice-making chamber for cooling ice-making water and to be in contact with an ice-making tray. In such a direct cooling method, the ice-making tray receives cooling energy from the refrigerant pipe by thermal conduction. Accordingly, the direct cooling method has a merit in that a cooling speed of ice-making water is fast. However, when the cooling speed of ice-making water is excessively fast, ice which is not transparent and is turbid is generated.